<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>2D变换_旋转</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .outer{
            width: 300px;
            height: 300px;
            border:2px solid black;
            margin: 800px;

        }
        .inner{
            width: 300px;
            height: 300px;
            background-color: deepskyblue;
            text-align: center;
            line-height: 300px;
            margin: auto;
            /*
            旋转:以元素的正中心旋转,正值顺时针旋转,负值逆时针旋转
            */
            transform: rotate(10deg);
        }
    </style>
</head>
<body>
<div class="outer">
    <div class="inner">inner</div>
</div>

</body>
</html>